Going into this week I wanted but was yet to be able to acquire a MIDA, one of the few weapons I still needed. Then on Tuesday in a nightfall I had my first MIDA pop...very cool, I finally got one. Later that day on a normal Crota down I got my second. Yesterday doing patrol I popped a legendary engram for my third. On top of that on another Crota run a buddy of mine popped a MIDA at the Deathsinger. One week, 4 MIDA and now Xur is selling it. I've seen a lot of people say that items that Xur sells drop more frequently the week he sells them but I've never seen it happen like this personally....or it's just one heck of an RNG coinkeydink.